Answer
$F=10.0\mu N$
$W_1=78.5 N$
$W_2 =118 N$
Work Step by Step
We are given that two particles have a mass of 8 kg and 12 kg, respectively and that they are 800 mm apart. We are asked to determine the force of gravity acting between them.
We will use equation 1-2
$F=G *\frac{m_1*m_2}{r}$
$F=66.73m^3/(kg *s^2)*\frac{8kg*12kg}{0.800m}$
$F=10.0 *10^{-9}N$ or $10.0\mu N$
Now we will compare that to the weight of each particle.
$W_1 = 8kg(9.81m/s^2) = 78.5 N$
$W_2 = 12kg(9.81m/s^2) = 118 N$
We can see that the force of gravity acting between them is very small compared to the weight of each particle.